Abstract: Disclosed are nucleic acid sequences comprising a modified HIV Gag sequence, wherein the modified HIV Gag sequence comprises, from 5? to 3?, a matrix domain (MA), capsid (CA) domain, SP1 region, nucleocapsid (NC) domain, SP2 region, and p6 domain, wherein the modified HIV Gag sequence further comprises an exogenous sequence of interest between the NC domain and the SP2 region. Disclosed are methods of producing a recombinant lentivirus comprising transfecting a cell with a plasmid comprising the nucleic acid sequence of one or more of the disclosed nucleic acid sequences in combination with an envelope plasmid. Disclosed are methods of monitoring lentivirus assembly, budding, and/or maturation comprising transfecting a cell with a plasmid comprising any one of the disclosed nucleic acid sequences in combination with an envelope plasmid, wherein the exogenous sequence of interest encodes a detection agent.

Abstract: A novel interstitial collagenase is disclosed which acts as an ATP-independent molecular motor driven by the proteolysis of substrate collagen. Also disclosed is a method of reacting interstitial collagenase with a collagen fibril to encounter multiple cleavage sites without substantial dissociation of said interstitial collagenase and thereby act as a molecular motor driven by the proteolysis of substrate collagen. The invention thus is useful as a research tool in the tissue remodeling and cell-matrix interaction. The invention also has significant utility in the screening and development of inhibitors of interstitial collagenase and as a research tool for evaluating the activity and effect of drug candidates.